In converting 2D images into left and right eye images for stereoscopic viewing it is known to create depth maps to assist in the transmission and creation of the 3D image. Generally speaking, the creation of a depth map refers to a technique whereby each object in a scene is allocated a unique attribute (typically a shade of gray) depending upon the relative, or absolute, distance from the object to a reference point, for example the camera lens.
For systems that seek to create stereoscopic images from a 2D image, the creation of this depth map is in most cases, if not all an interim step in this conversion process. The operator, or system, will analyze a 2D image, create a unique depth map, and then finalize the process by creating left and right eye images. Depending on the circumstances, this final process may take place some time after the creation of the depth map.
There presently exists a number of systems which attempt to convert 2D images into stereoscopic images. Whilst each of these systems may effectively create a depth map, the processes of obtaining those depth maps, and similarly, the process by which those depth maps are utilized differ. Further, in order to determine the depths of an object within an image and thereby a depth map, a number of techniques may be used, including the use of multiple cameras, laser range finders, radar imaging, and techniques using modulated radiation sources coupled with reflected radiation intensity detectors.
For example, in the Applicants prior application PCT/AU96/00820, the contents of which are incorporated herein by reference, thee was disclosed a number of techniques, including determining the distance of objects from a camera using variable focus techniques. Alternatively, the use of two cameras and an autocorrelator to determine the distance of objects from a camera was also disclosed.
As a result of these various techniques, the depth maps may be in various formats. The more common formats including, grayscale images, color encoded depth images, or a floating point distance matrix.
Whilst numerous techniques exist to convert 2D images to stereoscopic images, and in the process create depth maps, to date it has not been possible to combine these processes, such that one technique is utilized to create the depth map, and a different technique used to produce the stereoscopic image. That is, merging of the various techniques has not been possible, as existing systems are not able to process a depth map produced by a different process.
The inability to combine processes can lead to the same 2D image being processed by a number of different techniques, thereby producing respective depth maps. The task of analyzing a 2D image for conversion to a depth map can be complicated and in some cases time consuming, and it would be preferable to avoid the need to repeat this task depending on the overall 2D to 3D conversion process selected.